In case you’re at the US Open and wondering what those funky royal blue bracelets are that many people are wearing, they are called MyOpen Passes.

American Express brought the RFID-enabled wristbands to the Grand Slam for the first time, giving users a way to record their experiences in its tent without charge.

During the two-week tennis tournament, fans who enter the American Express Fan Experience area and use its stations will be sent an email with details and pictures of their activities via the wristband technology.

In the swing analysis station, for example, a machine measures someone’s impact position, racquet speed and spin rate, aiming to help players use that data to improve. The results will be sent to the fan through the bracelet.

To use the wristband, fans have to register for it when they enter the tent.

Besides the swing analysis, fans can pose for images in a station called pro cam, where numerous cameras are mounted in a half-circle. The resulting image moves in 180 degrees, showing the photo from various angles.

And for those fans who want to take a picture with a pro player, but have not been lucky enough to meet one, rest assured, because there is also a station where fans can take a picture with a hologram of Sloane Stephens.